A generalized illustration of a wireless handheld mobile communication device is shown in FIG. 1. The device includes a housing, a graphical display screen, and a keyboard section with a plurality of keys thereon. The device further includes a thumbwheel and one or more navigational tools such as an auxiliary input device located between the display screen and the keyboard section. The auxiliary input device may be any of a trackball, cursor keys, a track wheel, a roller barrel, a touch pad, or a joystick.
Such wireless handheld mobile communication devices are becoming smaller and smaller for handheld use. In fact, they may be on the order of between fifty millimeters (approximately two inches) and eighty-nine millimeters (approximately three and one-half inches) in width, to facilitate palm-cradling of the device by a user. To facilitate such smaller device widths, the keys on wireless handheld mobile communication devices are being made smaller and smaller. In fact, on some such devices, the keys may be less than seven millimeters (approximately one quarter of an inch) in width, and as small as three millimeters (approximately one eighth of an inch) in width. As a result, a user's thumb (or other digit) may overlap several keys at the same time when the user is trying to depress an intended key on the keyboard, as illustrated in FIG. 1, which leads to typing errors.